I see this quite a bit, a lot of equipment gets run into the ground, broken everything and patched with zip ties and duct tape just to get it up and running again, never really repaired properly or correctly..wiring is what I do, so what I see is that no-one really wants to spend the time to repair it right so it'l last..and wire nuts have NO place in mobile equipment,yet I see them time and time again. You might have luck with the DEVMO gauges Jim found above, I think it's a crap shoot on the quality anymore..I just spent $60 on a VDO electrical fuel level gauge for a forklift, 2weeks later now it doesnt work..pinned it out, its wired right, swopped a lead wire from the fuel tank terminal directly over to the gauge,sender works but gauge is dead..1 hour install time because I gotta pull the whole dash panel out to replace the gauge,of course I can't return it because its electrical in nature, no warrantee..If i had paid $100 for the gauge the outcome probably woudnt have been any better..just more aggravation.
